Considerable resources are expended each year to measure and detect microorganisms and biologicals. Ensuring products, public areas, blood and tissue banks, air and water supplies are free of microbial contamination is a major public concern. The occurrence of microorganism and harmful biological contamination in any of these is a major health risk and detection and control thereof are a necessity.
Furthermore, there exists no assay for direct detection of bacteria in samples, such as body fluids, and for diagnosis of infections. Current methods instead diagnose indirectly, for example, by urinalysis, to determine specifically the presence of nitrites, leukocytes, or leukocyte esterase and chemical testing for glucose or pH. Diagnosis of an infection, if confirmed, is done so by bacterial culture, which can be laborious and time consuming. Similarly, there is no direct test for bacteria in cerebrospinal fluid, which could be used for the rapid diagnosis of bacterial meningitis, a rapidly progressing infection of the central nervous system, which is typically fatal if antibiotic treatment is not initiated promptly. Culture methods are too slow to be of use in diagnosing such infections.
Conventional detection methods may also be misleading and do not provide rapid results allowing for immediate action. While current methods may be effective tools to detect and quantify some types of microorganisms, most methods are culture-based or, if developed, molecular-based techniques for specific microorganisms and biologicals. However, these methods can be difficult and time-consuming. In addition, many microorganisms fail to have specific, reliable detection methods, such as many viruses. Some microorganisms also may pose too hazardous for handling, so no detection method is available.
Many tests exist for sensitive detection of a broad spectrum of various bacterial species based on the detection of specific bacterial antigens. However, the tests are limited since they cannot be applied directly for testing of samples where the spectrum of bacterial pathogens is unknown. Also, the tests include an additional step for pre-enrichment of biological. Such a step can take one-to-three days, before performing the advertised tests. Thus, there remains a need for the development of a detection method capable of detecting a broad spectrum of microorganisms, known and unknown, that is easy to employ, fast and accurate.